Steam/hydrocarbon reforming with oxygen-based reforming methods such as autothermal reforming (ATR) or O2 secondary reforming are known and generally used for CO and synthesis gas (syngas) production. Autothermal reforming and O2 secondary reforming require industrial grade oxygen. Industry desires to reduce O2 consumption for autothermal reforming and O2 secondary reforming.
Oxygen-based reforming methods can achieve relatively high carbon capture compared to conventional steam/hydrocarbon reforming methods without the use of oxygen, since a majority of the CO2 produced in the oxygen-based methods can be recovered from the high pressure syngas stream using conventional acid gas removal operations. Industry desires to capture CO2 and/or limit CO2 emissions from H2 production facilities.
Hydrogen production using autothermal reforming or oxygen secondary reforming typically use methanation and cannot achieve a hydrogen product purity greater than about 98.5 vol. %. Industry desires to produce H2 at purities suitable for H2 pipelines from autothermal reforming and oxygen secondary reforming. To generate H2 purities required for H2 pipelines, the product from autothermal reforming or O2 secondary reforming may be processed in a pressure swing adsorber (PSA). However, use of a PSA results in a considerable loss of H2 via the PSA tail gas stream. And unlike conventional steam methane reforming where PSA tail gas is advantageously used as a fuel, suitable use for the excess PSA tail gas stream must be found for autothermal reforming and oxygen secondary reforming. Industry desires improved hydrogen production efficiency from autothermal and secondary oxygen reforming when producing high purity H2.
Industry desires to produce H2 for pipeline use, without the need for a customer for coproduced steam. Industry desires the option to produce H2 with limited or zero steam export.
The present process addresses these industry desires.